Corrugator combiner machine



D. B. WICKER CORRUGATOR COMBINER MACHINE Feb. 13, 1968 Filed NOV. l5, 1963 4 Sheets-Sheet 1 NN. mn Om Om m Feb. 13, 1968 D. B.w1cKr-:R 3,368,933

CORRUGATOR COMBINER MACHINE Filed Nov. l5, 1963 4 Sheets-Sheet 2 Feb. 13, 1968 D. B. WICKER CORRUGATOR COMBINER MACHINE Filed Nov. l5, 1965 4 Sheets-Sheet I5 Feb. 13, 1968 D, B, WICKER 3,368,933

CORRUGATOR COMBINER MACHINE Filed Nov. 15, 1963 4 Sheets-Sheet 4 FiG. I6

FIG. I8

Unite States Patent York Filed Nov. 15, 1963, Ser. No. 323,935 llt) Claims. (Cl. 156-498) This invention relat-es to corrugator combiner machines and more particularly to an improved belt for use in such machines.

In the assembly of paper, paperboard, box-board, etc., into corrugated structures, the two at liner sheets Iand the inside corrugated sheet are led. along various feed paths and are treated with a liquid adhesive, such as an aqueous solution of sodium silicate or of starch, for example. The three sheets then come together and are pressed by one or more endless belts, heretofore customarily of cotton or other woven material, onto a series of steam-heated plates to be dried. The heat from the plates is conducted* directly to the assembled corrugated web and through the web to the belt. In addition to their drying function, the vendless belts also serve to transport the web past the plates and then through the cooling section of the combiner machine. As used herein and in the appended claims, the word endless is intended to encompass not only belt constructions in which the seams or joints exhibit indistinguishable properties from the remainder of the belt, but also constructions in which the ends of the belt are interconnected by clipper seams or other connecting means having characteristics different from the remaining portions of the belt.

Corrugator combiner belts should be strong and -durable with good dimensional stability under the conditions of tension, high temperature, etc., encountered in the heating and cooling sections of the machine. The belts also must be comparatively flexible in the longitudinal or machine direction while retaining sutiicient rigidity in the cross-machine direction to facilitate the guiding of the belts along their endless paths. In addition, the belts preferably should have suicient porosity to permit the free transmission of vapor therethrough but at the same time should be suiciently incompatible with moisture to avoid the absorption of condensed vapor which might other wise rewet the surfaces of the corrugated product. These characteristics should be realized while maintaining the manufacturing cost of the belts at a minimum.

In the manufacture of cotton and other corrugator combiner belts of the type previously employed, ditliculties were encountered in the realization of the optimum drying and web transporting characteristics. As tan illustration, problems were encountered in adjusting the porosity of such prior belts to enable the adequate escape of vapor from the web while avoiding vthe transmittal of condensed vapor back to the web surfaces. =In addition, the corrugator combiner belts employed heretofore often exhibited comparatively poor resistance to heat degradation and showed a tendency to wear after repeated usage, particularly along the edges of the belts. Furthermore, the belts frequently were insufliciently rigid in the crossmachine direction, with the result that they were difficult to guide along their endless paths.

The difficulties experienced with corrugator combiner belts of traditional construction were often compounded by their comparatively high cost. In many cases, the belts required expensive textile processing operations, including the use of large and costly looms. Also, substantial quantities of relatively expensive fibers were needed, the cost of which was further increased when bers having good heat resistant properties were employed.

One general object of this invention, therefore, is to provide a new and improved belt for use in a corrugator combiner machine.

Another general object of the invention is to provide a novel corrugator combiner machine which utilizes such belt.

More specifically, it is an object of this invention to provide a belt of the character indicated in which the belt exhibits improved dimensional stability, greater resistance to heat degradation and increased durability.

Another object of this invention is to provide such belt which enables the realization of extremely good porosity characteristics while avoiding the absorption of substantial quantities of condensed vapor.

A further object of the invention is to provide a corrugator combiner belt having improved cross-machine rigidity and adequate lengthwise flexibility.

Still another object of the invention is to provide an improved belt in which the tendency of the belt to clog or till up as a result of the adhesives employed, dirt, etc., is substantially reduced.

Another object of the invention is to provide an improved joint or seam between the ends of the belt to form an endless construction.

A still further object of the invention is to provide a belt which is economical to manufacture and thoroughly reliable in operation.

ln one illustrative embodiment of the invention, thereis provided a new and improved belt for transporting a moist web of faced corrugated paper through the heating and cooling sections of a corrugator combiner machine. The term paper, as used herein and in the appended claims, refers to conventional paper and board products and` also to other related products having Ia non-woven fibrous structure. The belt includes a plurality of perforations substantially entirely throughout its surface area and is fabricated from an oblong, rect-angular sheet of synthetic, non-woven material. The ends of the perforated sheet are connected together to form a seamed or endless belt which is arranged in an operative position in the machine.

In accordance with one feature of the invention, the belt is manufactured from a sheet of polymeric material which is substantially non-deformable in thickness and has a substantially crystalline structure, for example, polyethylene terephthalate. The material preferably has softening and melting points at comparatively high temperature levels and exhibits good durability and dimensional stability under the conditions of tension, temperature, edge abrasions, etc., in the heating and cooling sections of the machine. In certain particularly advantageous arrangements, the material is substantially non-absorbent, thereby further improving its moisture-removing action by reducing the possibility of transmitting condensed moisture back to the corrugated web.

In accordance with another feature of certain embodiments of the invention, the perforations in the belt material are of a size and orientation sucient to enable extremely efficient transmission of moisture through the belt from the web. In some embodiments, the perforation arrangement is such that uninterrupted paths of the material extend in a lengthwise or machine direction, thereby further preserving the materials good durability characteristics. In addition, the perforations preferably are arranged to provide imperforate areas along the outer longitudinal edges of the belt, with the result that the possibility of substantial wear along these edges after repeated usage is substantially reduced.

In accordance with still another feature of the invention, in some particularly advantageous arrangements, the incompressible polymeric sheet is provided with a laminated layer of either the same or different material on one 0r both of its surfaces. The laminated layer is such that the belt exhibits comparatively high rigidity in the crossmachine direction while retaining good flexibility in the longitudinal direction. In some cases, the sheet material is provided with a lamination of a material which is readily compressible, such as a bat of either natural or synthetic fibers or a layer of open-cell foam, for example. The compressible layer may be arranged on the surface of the belt which faces the moist corrugated web and serves as a barrier to substantially reduce any transmission of moisture back to the web from the belt.

In accordance with a still further feature of the invention, in several good arrangements, one or both surfaces of the belt is provided with a slippage-resistant surface which produces a comparatively high coeflicient of friction between the belt and the surfaces in contact therewith.

In one embodiment the belt includes a scored or undulating surface, while in other arrangements a layer of abrasive material-is secured to the belt. In still other cases a compressible lamination serves to increase the coecient of friction. The arrangement is such that any slippage between the belt, its driving and supporting rolls and the corrugated web is maintained at a minimum, thus enabling the uniform advance of the web through the machine.

In accordance with still another feature of certain embodiments of the invention, two or more sheets of polymerio material are ultrasonically sealed in side-by-side relationship with each other to provide a single belt having a width substantially equal to that of the corrugated web. The ends of the sheets also are connected by ultrasonic means. Such ultrasonic connections provide an extremely strong joint while presenting a smooth continuous surface to the web.

The present invention, as well as further objects and features thereof, will be understood more clearly and fully from the following description of certain preferred embodiments, when read with reference to the accompanying drawings, in which:

FIGURE 1 is a diagrammatic side elevational view of a double facer corrugator combiner machine clothed with synthetic belts in accordance with one illustrative embodiment of the invention;

FIGURE 2 is an enlarged fragmentary plan view of the beltsseen from the line 2 2 in FIGURE 1;

FIGURE 3 is an enlarged fragmentary sectional View taken along the line 3 3 in FIGURE 2;

FIGURE 4 is an enlarged vertical sectional view of a portion of one of the belts of FIGURES 1-3, together with a schematic representation of suitable perforating apparatus;

FIGURE 5 is a vertical sectional view of a portion of a synthetic belt in accordance With another illustrative embodiment of the invention;

FIGURE 6 is a fragmentary plan view of a synthetic belt in accordance with a further illustrative embodiment of the invention;

FIGURE 7 is an enlarged vertical sectional view of the ends of one of the belts of FIGURES 1-4, together with a schematic illustration of an apparatus for forming la representative connection therebetween;

FIGURE 8 is an exploded plan view of the ends of a synthetic belt showing another representative connection therebetween;

FIGURE 9 is a longitudinal sectional view taken generally along the line 9 9 in FIGURE 8;

FIGURE 10 is an exploded plan view in general similar to a portion of FIGURE 8 but showing an additional representative connection between the ends of a synthetic belt;

FIGURE 11 is a longitudinal sectional view taken generally along the line Il ll in FIGURE 10;

FIGURE 12 is a vertical sectional view of the ends of a synthetic belt showing still another representative connection therebetween;

FIGURES 13 and 14 are fragmentary plan views of synthetic belts in accordance with additional illustrative embodiments of the invention;

FIGURE 15 is a fragmentary vertical sectional view taken along the line 15 15 in FIGURE 14;

FIGURES 16-18 are fragmentary vertical sectional views of synthetic belts in accordance with further illustrative embodiments of the invention; and

FIGURE 19 is a fragmentary plan view of a synthetic belt in accordance with still another embodiment of the invention.

Referring to FIGURE l of the drawings, there is shown a schematic representation of a corrugator combiner machine of the double facer type which is arranged to form and assemble a continuous web 20 of corrugated paper, board, etc. The web 20 includes a centrally located sheet 21 and two liner or facer sheets 22 and 23. The sheet 21 is led from a suitable supply, such as a roll 25, for example, through a pre-heating mechanism 26 where it is heated by steam under pressure. The sheet is then advanced to a single facer corrugator unit 27 and is fed around two corrugating rolls 28 and 29 which form a series of transversely extending corrugations or flutes 30 (FIGURES 2 and 3) thereon. The thus corrugated sheet then contacts an additional roll 32 in the unit 27 which is effective to apply a layer of sodium silicate solution, starch solution or similar adhesive to the tips of the flutes on the adjacent surface of the sheet.

Simultaneously with the advance of the corrugated sheet 21, the uppermost facer sheet 22 is led from a supply roll 35 around a combining roll 36 in the corrugating unit 27. The roll 36 applies pressure between the flat sheet 22 and the adjacent corrugated sheet 21, and the adhesive on the flutes 30 holds the sheets together. The assembled singlefaced structure is then directed over a series of support rolls 37, 38 and 39.

The lowermost facer sheet 23 is advanced from a supply roll 42 to a gluing unit indicated generally at 43. The assembled sheets 21 and 22 from the corrugating unit 27 are received by a roll 40 in the gluing unit 43, and liquid adhesive is applied to the tips of the utes on the exposed surface of the sheet 21. The sheets 2l and 22 then proceed to an elongated combiner table 45 where they are united with the sheet 23 to form the corrugated web 20. Although in most corrugator combiner machines the proportional length of the table 45 is considerably greater than that shown in FIGURE 1, the table has been shortened in this figure because of space limitations.

The table 45 includes a heating section 46 and a cooling section 47. As the assembled web 20 is advanced along its feed path through the section 46, it is pressed against the upper surfaces of a series of heated platens or plates 48 by a pair of endless top belts 49 and 50 (FIGURE 2). The plates 48 are maintained at a uniform temperature which in some machines approaches about 350 F. The belts 49 and 50 follow parallel paths and are maintained in contact with the upper surface of the web 20 during its passage through the section 46 and also as it moves through the section 47.

The lower reaches of the top belts 49 and 50 pass bcneath a series of hold down rolls 51 which are transversely supported above the table 45 in the heating section 46 and the cooling section 47. At the infeed end of the heating section, the belts 49 and 5t) extend around a support roll 52, and their upper reaches are trained past a pair of guide rolls 53 and 54 supported above a standard 55 affixed to the table 45. The angularity of the guide roll 54 is adjustable, as by a hand wheel 56, to correct any misalignment of the belts as they move along their endless paths. The upper reaches of the belts then pass under and over two rolls 57 and 58 carried by a rack 59. This rack is pivotally supported on a standard 59a to enable the adjustment of the amount of tension in the belts. From the rack S9, the upper belt reaches are led thro-ugh the cooling section 47, beneath an idler roll 6@ and around a drive roll 61 at the outfeed end of the cooling section.

Upon entering the cooling section 47, the lowermost liner sheet 23 of the corrugated web 20 is engaged by a bottom belt 62. The belt 62 is trained around a support roll 63, and the ripper reach of the belt passes between the upper surface of the table 45 and the sheet 23. The belt is then led around a drive roll 64 to a pivotally supported rack 65. The rack 65 includes two rolls 66 and 67 which engage the belt to enable adjustment of its tension. As the belt returns to the support roll 63, it is carried past a flanged guide roll 68.

The two top belts 49 and 50 and the bottom belt 62 greatly facilitate the removal of moisture from the assembled corrugated web 20. In addition, the belts 49, 5) and 62 serve to transport the web 20 along the table 45. Upon leaving the table, the assembled and dried web is led over an idler roll 69 to a suitable cut-off and storing unit 70, where the web is Cut to length (by means not shown) and is wound around a storage roll '71.

The belts 49, 50 and 62 are fabricated from a nonwoven thermoplastic polymeric sheet material having a substantially crystalline structure. The belt material exhibits little or no compressibility and is comparatively light in weight and highly flexible. In addition, the material is substantially imprevious to moisture and is characterized by an extremely smooth surface finish, when compared to woven cotton belts of the type employed heretofore.

One illustration of a nondeformable polymeric sheet material which is of particular utility in the formation of the transportingy belts 49, 50 and 62 is polyethylene terephthalate. This material is exemplified by the line of products commercially available from E. I. du Pont de Nemours & Company, Wilmington, Del., and sold under its trademark Mylar. Such products are referred to herein as Mylar polyester film and are characterized by their crystalline structure, extremely smooth surface finish and good resistance to heat degradation. The distortion point of the material customarily lies within the range of from about 380 F. to 490 F., well above the temperature encountered in the heating and cooling sections of corrugator combiner machines presently in use. Because conventional adhesives, heat-sealing operations, etc., have little utility when applied to Mylar polyester film, difficulties heretofore were encountered in joining the ends of the material to form an endless belt, particularly in cases in which the belt was subjected to high stress. However, because of the unique joining means described hereinafter, the ends of the belt are firmly interconnected to provide an endless construction.

Of the various types of Mylar polyester film presently available, type A and type T are particularly useful as web transporting belts in the heating and cooling sections of the machine. Type A is biaxially oriented, having substantially equal properties in'both the machine direction and in the cross-machine direction. Type T has unusually high tensile strength in the machine direction and is of particular utility in cases in which the machine is operated at high speed or in the manufacture of some of the heavier board products. l

Other polymeric materials useful in the formation of synthetic belts in accordance with the invention include polyamide polymers, e.g., the nylons designated as type 6, type 66 and HTA, various polycarbonate polymers, polyolefin polymers such as polyethylene and polypropylene, for example, polyvinyl fluoride or other vinyl polymers, and various varieties of vinylidene polymers. Representative of suitable polymers of this latter class are polymers of vinylidene bromide, vinylidene chlorobromide, vinylidene cyanide and vinylidene halocyanide. These and other monomers also may be co-polymerized to form copolymers such as vinylidene chloride-vinyl chloride, for example.

Each of the belts 49, 50 and 62 is laminated from two 6 layers of Mylar polyester film. The laminations are interconnected by a suitable. adhesive 72 (FIGURES 3 and 4), such as one of the polyurethane resins, for example. One polyurethane resin which is particularly useful for this purpose is Unithane Resin D-407-JL, which is a trade name of the Thiokol Chemical Corporation, Tren--4 ton, NJ. The laminated belts provide considerable rigidity in the cross-machine direction to facilitate guiding, etc., without unduly restricting the fiexibility of the belts in the longitudinal direction. To retain the desirable liexibility characteristics of the belts while at the same time provide belts which are strong and durable in use, it has been found that in several advantageous embodiments the belt thickness should range between about 10.0 mils and 42.0 mils, and preferably between about 14.0 mils to 28.0 mils. Because the Mylar polyester film presently available has a thickness of from about 0.25 mil to about 14.0 mils for single ply construction, when used as corrugator combiner belts in accordance with these embodiments a sufficient number of laminations is provided to build up the sheet material to the requisite thickness.

As best shown in FIGURE 2, the top belts 49 and 50 each have a width which is slightly less than one-half the width of the faced corrugated web 20, with a slight space between the belts. The width of the bottom belt 62, on the other hand, is approximately equal to that of the corrugated web. The belt 62 is fabricated from two oblong, rectangular sheets 73 and 74 of Mylar polyester lm which are ultrasonically sealed in side-by-side relationship with each other, in a manner that will become more fully apparent hereinafter, to provide smooth continuous belt surfaces.

In some embodiments, a single top belt is provided of a width substantially equal to that of the corrugated web. Because of the unique characteristics of the polymeric belt material, the single belt may be easily guided even on comparatively large combiner machines. The belt may be formed of a single sheet of polymeric material, or two or more sheets may be ultrasonically interconnected in a manner similar to that of the sheets 73 and 74 of the bottom belt 62.

Each of the belts 49, 50 and 62 includes a series of spaced perforations 75 which extend substantially entirely throughout the same. These perforations are aligned in rows which extend in the longitudinal or machine direction of each belt and also in the transverse or cross direction. The spacing between adjacent rows of perforations is substantially equal to the diameter of each perforation and provides uninterrupted longitudinal paths 76 and transverse paths 77 of the belt material. Particularly because of the longitudinal paths 76, the4 reduction in the tensile strength of the material occasioned by the perforations is considerably less than ywould otherwise be the case. The outer edges of the belts additionally include longitudinally extending imperforate areas 78. These areas serve to minimize the possibility of fraying or rupture and reduce the incidence of edge wear as the belts mJlve around the various driving, guiding and support ro s.

As a result of the perforations 75, the available porosity ranges of the transporting belts are considerably greater than those of the woven belts heretofore available. At the time the moist corrugated web 20 comes in contact with the plates 4S in the heating section 46, much of the water and other liquid in the web is rapidly vaporized. This vaporization continues at a reduced rate during the passage of the web through a substantial portion of the cooling section 47. With conventional, relatively bulky belts, even those of comparatively open weave construction, the belts often exhibited a blanketing effect which greatly restricted the free passage of vapor therethrough from the web to the atmosphere. The perforations in the belts 49, 50 and `62, on the other hand, are such that the vapor is quickly discharged to the atmos- 75 phere.

The deleterious blanketing effect of many of the conventional combiner belts has been further augmented by their highly absorbent characteristics. Although the absorbency of the prior belts in some respects has been considered advantageous, it has been found that the condensed vapor absorbed by the belts, unless removed, has a rewetting effect on the surfaces of the web in contact therewith. Because of the substantially non-absorbent nature of the polymeric material used for the belts 49, 50 and 62, much of the'moisture that would otherwise be retained within the belts is discharged to the atmosphere through the perforations 75.

In the embodiment shown in FIGURES 1-4, each of the perforations 75 in the belts 49, 50 and 62 is 0.045 inch in diameter, and 225 perforations are provided 4in each square inch of the material, giving an open area of thirty-six percent. With this arrangement, the air permeability of the belt is over 700 cubic feet per minute per square foot at 0.5 inch water, as measured under ASTM Standard Test Procedure No. D737-46 for Air Permeability of Textiles. In several advantageous embodiments, the size and orientation of the perforations is within well defined limits to enable the eiiicient transmission of moisture through the belt from the corrugated web. Although the perforation size and orientation varies widely in accordance with the type of combiner machine and other factors, for many applications the perforations are such that the belts have an open area within the range of from about 5 percent to about 36 percent. In other arrangements, good results are obtained with perforations of a size and orientation outside this range.

The perforated polymeric belt material also exhibits very little tendency to fill up or become clogged with starch particles, fibers from the corrugated web, dirt, etc., and is comparatively easy to clean. Primarily because of the arrangement of the perforations and the smooth surface characteristics of the polymeric material, particles of foreign matter are not collected within the perforations to any appreciable extent.

The perforations 75 are formed by punching apparatus indicated schematically at 79 (FIGURE 4). The appara- -tus 79 includes a series of cylindrical, downwardly extending punches 80 which are movable in directions perpendicular to the plane of the polymeric sheet. The lower surfaces of the punches 80 are recessed to form comparatively sharp cutting edges 81. Upon movement of the punches into the sheet of material, the material is cut away to form the perforations. In most cases, the punches are at a temperature which is well below the softening point of the material, and preferably at substantially room temperature. With this arrangement, the material to be removed from the sheet is cut cleanly, thus substantially eliminating the possibility of forming small lumps or beads of material on 4the sheet surfaces which might mar the corrugated web.

For certain corrugator combiner machines, particularly in cases in which considerations other than the rapid passage of moisture through the belts are of primary concern, the perforations 75 may be omitted without departing from the spirit or scopeof the invention.

The polymeric belt material preferably is preconditioned by the application of heat to reduce the possibility of shrinkage during use and also to relieve any stresses that may have developed during the formation of the perforations. The ends of the material are first temporarily connected, as by suitable staples (not shown), and the belt is then installed under tension around a portion of the cylindrical surface of one or more heated drums, as more fully described, for example, in copending U.S. application Ser. No. 283,907, filed May 28, 1963, by Ralph H, Beaumont, Donald R. Christie and John Okrepkie. Alternatively, the belt may be temporarily installed on the -combiner machine and advanced along the table 45 (FIG- URE l) with the plates 48 at the desired pre-conditioning temperature. The temperature of the drums or plates is such that the belt is heated to a pre-conditioning temperature which is at least as great as that expected in its end use but is below the softening point of the material. The length of time the belt is maintained at the preconditioning temperature is relatively short and illustratively is of the order of about five minutes. Thereafter, the staples are removed, and the belt is cut to the appropriate length preparatory to its final installation on the machine.

In other embodiments, particularly when type Ay Mylar polyester film is used as the belt material, the possibility of substantial belt shrinkage on the machine is so slight that the pre-conditioning step is eliminated.

For corrugator combiner machines having comparatively low power requirements, a single sheet of incompressible polymeric material is employed for each belt, rather than the multi-layer sheets forming the belts 49, 50 and 62 on the machine of FIGURE 1. Thus, as best shown in FIGURE 5, there is provided a belt 82 comprising a single layer of Mylar polyester film which includes the perforations substantially throughout the same. To reduce the possibility of slippage between the belt 82 and the various driving, supporting and guiding rolls of the machine, the inner surface of the belt is provided with a layer 83 of material which produces a high coefficient of friction between the belt and the rolls. The layer 83 illustratively comprises a coating of colloidal silica which is applied to the belt surface and permitted to dry. One commercially available product of this type is Syton DS, a trade name of the Monsanto Chemical Corporation, St. Louis, Mo. As another illustration of a suitable coating layer 83, an abrasive material such as ground silica, for example, may be applied to the inner surface of the belt. The abrasive may be held in place by heating the belt to a temperature above its softening point, thus using its thermoplastic properties, or by curing with various thermosetting resins.

In some cases, the inner surfaces of the corrugator combiner belts are provided with a scored pattern to increase the coefiicient of friction between the belt and the surfaces in contact therewith. As an illustration, in FIGURE 6 there is shown a single sheet belt 84 of Mylar polyester film which is provided with scoring 84a. The scoring 84a extends diagonally between the perforations 75 to form minute channels or grooves in the inner belt surface. The thus modified surface of the belt substantially reduces the possibility of slippage with respect to the driving, supporting and guiding rolls.

In some advantageous arrangements, the belts 82 and 84 of FIGURES 5 and 6 are inverted such that their modified surfaces face outwardly in position to contact the facer sheets of the corrugated web. Because of the comparatively high coefficient of `friction presented between the modified belt surfaces and the web, any possibility of relative movement therebetween is maintained at a minimum. By providing abrasive layers, scoring, or otherwise modifying both the inner and outer surfaces of the belts, an extremely smooth transmission of power takls place from the driving rolls through the belts to the we The interconnections between the ends of either single layer or multi-layer corrugator combiner belts are formed by unique ultrasonic sealing apparatus. One such apparatus which is particularly well suited for interconnecting the ends of the belt 62, for example, is shown schematically at 86 in FIGURE 7. The apparatus 86 includes a sine wave voltage source 89 which is electrically connected to a transducer 93. The transducer 93 is arranged to impart vibratory mechanical motion at a fixed ultrasonic frequency to a welding element or horn 93a. The horn 93a is disposed in juxtaposition with one side of the belt, while the opposite side rests on a stationary table 98. The ends of the belt to be joined are positioned in overlapping relationship with each other and are clamped on a movable fixture (not visible in FIGURE 7). The amount of overlap preferably is at least as great as the thickness of the belt and in the FIGURE 7 embodiment is slightly over twice the belt thickness. The belt is moved transversely along the table 98, and the vibr'atory motion of the horn 93a forms a permanent weld or seal between the overlapping ends of the belt with little interruption in the. smooth continuity of the belt surfaces. The weld advantageously is formed after the belt has been arranged on the machine and around the Various rolls which support it from the inside of its loop. However, under some circumstances the weld may be formed off the machine prior to installation, and the belt may be installed by sliding it over the temporarily unsupported ends of the rolls.

The sealing apparatus 86 also is advantageous in the formation of longitudinal ultrasonic seals, such as the seal 99 (FIGURE 2) between the two sheets 73 and 74 forming the belt 62. Particularly for these longitudinal seals, the belt may be held stationary, and the apparatus 86 moved to form the seal. In addition, the apparatus is advantageous in the formation of transverse or oblique seals between adjacent sheets, as in cases in which the belt comprises successive side-by-side sheets which extend in the -cross-machine direction, for example.

FIGURES 8-11 are illustrative of various alternative connections between the ends of corrugator combiner belts in accordance with the invention. In FIGURES 8 and 9 there is shown a corrugator combiner belt 85 of Mylar polyester film. The ends 87 and 88 of the belt 85 are folded back upon themselves and are each held in place by three transverse rows of stitching 90. The folds in the ends 87 and 8S are notched to provide integrally formed loops 91 and 92, respectively, which are positioned in interleaved relationship with each other. An elongated rod or pintle 94 is inserted through the loops 91 land 92 to connect the ends of the belt and thereby form an endless construction.

Referring to FIGURES and vll, there is provided a perforated belt 95 of Mylar polyester film having substantially flat end portions 96 and 97. The end portion 96 includes a transversely extending web 100 of woven material, such as Daeron, for example, which is held in place by stitching 101. The end portion 97 similarly includes a woven web 102 secured to the belt by stitching 103. A plurality of clipper hooks 105 is sewn into the web 100 and are interleaved with corresponding clipper hooks 106 in the web 102. The hooks 105 and 106 accommodate a pintle 108 to hold the ends of the belt in fixed but flexible relationship with each other.

FIGURE 12 is illustrative of another type of interconnection between the ends of a corrugator combiner belt. In this figure, there is shown a perforated belt 110 having two end portions 111 and 112 which are maintained in abutting relationship with each other by a woven web or tape 115. The tape 115 is sewn or otherwise afiixed to the inner surface of the belt, as by stitching 116, such that the opposite or outer surface presents a smooth, continuous face to the corrugated web (FIGURE 1). Preferably the tape 115 is fabricated from a comparatively thin, highly porous textile material. One illustration of a material of this type which is of particular utility in the formation of the tape is described in Ralph H. Beaumont and Donald R. Christie US. Patent 3,032,441, granted May 1, 1962.

As indicated heretofore, one or both surfaces of the belts 82 and 84 of FIGURES 5 and 6 are modified to increase the coefficient of friction between the belts and the surfaces in contact therewith and thereby reduce the possibility of slippage between the belts, the cormgated web and the various rolls in the heating and cooling sections of the machine. FIGURES 13-15 are illustrative of other modifications of the surfaces of corrugator combiner belts to further enhance their slippage resistant characteristics. In FIGURE 13 there is shown a single- 10 layer belt having perforations 121 of a size 'and orientation similar to that described heretofore. These perforations are arranged in longitudinally extending rows 122 and transverse rows 123. Intermediate each rectangular group of four adjacent perforations, there is provided a protuberance 125 of generally diamondshaped configuration. These protuberances illustratively are integrally formed with the belt, as by embossing, for example, and greatly improve the belts resistance to slippage.

In some cases, the protuberances are in the form of small hemispheres, as shown by the protuberances 126 on the single-layer belt 127 of FIGURES 14 and 15. r1`he belt 127 is provided with perforations 128 substantially entirely throughout its surface area, and these perforations are arranged in longitudinal rows 129 and transverse rows 130. Each of the protuberances 126 is of a diameter slightly greater than that of the perforations 128 and is positioned intermediate each rectangular group of four adjacent perforations. The arrangement is such that the coefficient of friction between the thus modified belt surface and the surfaces in contact therewith is substantially increased.

In several advantageous embodiments, one or both surfaces of the polymeric sheet material forming each belt is modified to add bulk and increase the absorptive or wicking qualities of the belt. In the arrangement shown in FIGURE 16, for example, a woven textile fabric is laminated to a sheet 136 of Mylar polyester film to form a belt 137. The fabric 135 is woven from either natural or synthetic fibers, such as wool or nylon, for example, or from blends of natural and synthetic bers, and is held in place :by a suitable adhesive 138. The assembled structure is perforated in a manner similar to that described above to provide perforations 139.

Another type of belt having the desired bulk and wicking properties is shown in FIGURE 17. In this figure, a layer 140 of open-cell plastic foam is laminated .to a sheet 142 of Mylar polyester film to form a belt 145. The layer 140 and the sheet 142 may be held together through the use of an adhesive 146, such as Unithane Resin D- 407-IL referred to above, or the layer may be chemically formed in place.

In other embodiments, a non-woven fibrous bat is applied to a surface of the belt. In FIGURE 18, there is shown a belt 14'7 which comprises a sheet 143 of Mylar polyester film laminated to a bat 150 of natural or synthetic fibers. In some cases, the bat is pre-formed, as by needling, felting, chemical bonding or other conventional process. Particularly in cases in which the fibers forming the :bat are to be given a predetermined orientation to further enhance its moisture-removing characteristics, however, the individual fibers are deposited electrostatically on the sheet 148. The assembled sheet and .bat are t-han punched to form perforations 152.

The laminated layers of deformable material on the polymeric sheets forming the combiner belts 137, 145 and 147 are of sufiiciently open construction so as not to substantially impede the transmission of vapor therethrough from the moist corrugated web. Particularly in cases in which the laminated layers are employed on the external surfaces of the belts, the layers provide sufficient bulk to prevent condensed vapor from passing back through the belt to the web. The arrangement is such that any possibility of rewetting the web as it moves through the heating and cooling sections of the machine is substantially eliminated.

The laminated layers on the belts 137, 145 and 147 also are advantageous when used on the inner belt surfaces. In addition to providing bulk and absorptive characteristics, the layers produce a high coefiicient of friction :between the belt and the various rolls in contact therewith, when compared to that pro-duced by the relatively smooth Mylar sheet material. As a result, power from the driving rolls is uniformly transmitted through the belts to the corrugated web to advance the web through the heating and cooling sections of the machine.

Corrugator combiner belts in accordance with the invention may be provided with perforations having various shapes other than the particular circular configuration described above. For example, FIGURE 19 is illustrative of a combiner belt 155 -having a series of square perforations 156 which are spaced apart in longitudinal and transverse rows. The 'belt 155 may be used in a manner similar to the belts previously discussed and provides extremely good moisture-removing and power-transmitting characteristics.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described, or portions thereof, it being recognized that various modifications are possible within the scope of the invention claimed.

What is claimed is:

1. A corrugator combiner machine comprising, in combination, means for assembling a faced corrugated web,

feed path defining means for receiving the assembled web, a heating section and a cooling section disposed in that order along the feed path for first raising and then lowering the temperature of said web, a nonwoven synthetic belt of substantially crystalline polymeric sheet material for directing said web along said feed path adjacent said heating and cooling sections, said belt having two end portions and the thickness of said belt being within the range of from about 10.0 mils `to about 42.0 mils, said feed path defining means advancing said `belt along the path in contact with said web, means for joining the end portions of said belt, and means for guiding said belt during its movement along said path.

2. A corrugator combiner machine comprising, in combination, means for assembling a faced corrugated web, feed path defining means for receiving the assembled web, a heating section and a cooling section disposed in that order along the feed path -for first raising and then lowering the temperature of said web, a nonwoven synthetic belt of substantially crystalline polymeric sheet material for directing said web along said feed path adjacent said heating and cooling sections, said sheet material being substantially nondeformable in thickness and including a series of spaced perforations substantially entirely 'throughout the same, said -belt having two end portions and the thickness of said belt being Within the range of from about 10.0 mils to about 42.0 mils, said feed path defining means advancing said belt along the path in contact with said web, means for joining the end portions of said belt, and means in engagement with the longitudinal edges of said belt for guiding the same during its movement along said path.

3. A corrugator combiner machine comprising, in combination, means for assembling a faced corrugated web, feed path dening means for receiving the assembled web, a heating section and a cooling section disposed in that order along the feed path for first raising and then lowering the temperature of said web, a nonwoven synthetic belt of substantially crystalline polymeric sheet material for directing said web along said feed path adjacent said heating and cooling sections, said sheet material being substantially nondeformable in thickness and including a series of spaced perforations substantially. entirely throughout the same to provide an open area for said belt within the range of from about percent to about 36 percent, said belt having two end portions and the thickness of said belt `being within the range of from about 10.0 mils to about 42.0 mils, said feed path defining means advancing said belt along the path in contact with said web, means for joining the end portions of said belt, and means for guiding said belt during its movement along said path.

4. A corrugator combiner machine of the character set forth in claim 3, in which said substantially crystalline polymeric sheet material comprises polyethylene terephthalate film.

5. A corrugator combiner machine comprising, in combination, means lfor assembling a faced corrugated web, feed path defining means for receiving the assembled web, a heating section and a cooling section disposed in that order along the feed path for first raising and then lowering the temperature of said web, a nonwoven synthetic belt of substantially crystalline polymeric sheet material for directing said web along said feed path adjacent said heating and cooling sections, said sheet material being substantially nondeformable in thickness and including a series of spaced perforations substantially entirely throughout the same to provide an open area for said belt within the range of from about 5 percent to about 36 percent, said belt having two end portions and the thickness of said belt being within the range of from about 10.0 mils to about 42.0 mils, said feed path defining means advancing said belt along the path in contact with said web, means including an ultrasonic seal on said 4belt for joining its end portions, and means in enga-gement with the longitudinal edges of said belt for guiding the same during its movement along said path.

6. A corrugator combiner machine comprising, in combination, means for assembling a faced corrugated web, feed path defining means for receiving the assembled web, a heating section and a cooling section disposed in that order along the feed path for first raising and then lowering the temperature of said web, a multi-layer belt including at least one layer of nonwoven substantially crystalline polymeric sheet material for directing said web along said feed path adjacent said heating and cooling sections, said sheet material being substantially nondeformable in thickness and including a series of spaced perforations substantially entirely throughout the same but with uninterrupted paths of the material extending in lengthwise directions along the longitudinal edges of said belt, said belt having Itwo end portions and the thickness of said belt being within the range of from about 10.0 mils to about 42.0 mils, said feed path defining means advancing said belt along the path in contact with said web, means for joining the end portions of said belt, and means in engagement with said longitudinal edges for guiding said belt during its movement along said path.

7. A corrugator combiner machine of the character set -forth in claim 6, in which each of the layers of said belt comprises polyethylene terephthalate film.

8. A corrugator combiner machine of the character set forth in claim 6, in which one of the layers of said belt comprises an open-cell foam.

9. A corrugator combiner machine of the character set forth in claim 6, in which one of the layers of said belt comprises a nonwoven fibrous bat.

' 10. A corrugator combiner machine of the character set forth in claim 6, in which one of the layers of said bel-t is of woven material.

References Cited UNITED STATES PATENTS 42,903,021 9/1959 Holden 162-348 2,941,573 6/1960 Cassady 156588 3,121,660 2/1964 Hall 162-348 3,162,567 12/1964 Heller 162--348 OTHER REFERENCES Alles: Journal of Soc. Motion Picture and Television Engineers, December 1961, vol. 70, pp. 976-978.

DOUGLAS l. DRUMMOND, Primary Examiner.

ALEXANDER WYMAN, EARL M. BERGENT,

' Examiner. 

1. A CORRUGATOR COMBINER MACINE COMPRISING, IN COMBINATION, MEANS FOR ASSEMBLING A FACD CORRUGATED WEB, FEED PATH DEFINING MEANS FOR RECEIVING THE ASSEMBLED WEB, A HEATING SECTION AND A COOLING SECTION DISPOSED IN THAT ORDER ALONG THE FEED PATH FOR FIRST RAISING AND THEN LOWERING THE TEMPERATURE OF SAID WEB, A NONWOVEN SYNTHETIC BELT OF SUBSTANTIALLY CRYSTALLINE POLYERMIC SHEET MATERIAL FOR DIRECTING SAID WEB ALONG SAID FEED PATH ADJACENT SAID HEATING AND COOLING SECTIONS, SAID BELT HAVING TWO END PORTIONS AND THE THICKNESS OF SAID BELT BEING WITHIN THE RANGE OF FROM ABOUT 10.0 MILS TO ABOUT 42.0 MILS, SAID FEED PATH DEFINING MEANS ADVANCING SAID BELT ALONG THE PATH IN CONTACT WITH SAID WEB, MEANS FOR JOINING THE END PORTIONS OF SAID BELT, AND MEANS FOR GUIDING SAID BELT DURING ITS MOVEMENT ALONG SAID PATH. 